What is a fair price for a new Glock 19 and used Glock19

I just came back from browsing at a pawn shop. They had a new Glock19 w/carrying case and a used one that showed very little wear, looked almost as good as the new one. The new one OTD was $535 including tax, is this a fair price and what should the price be for the used one? If I go in with cash in hand do you think could get the new one for around $500. When ordering a new or used weapon shipping and FFL transfer fees should be considered in my question and sales tax of 8.25% in Texas. I didn't inspect bores, when I have cash in hand and ready to deal with whoever I buy from, I will have a small LED flashlight or a bore flashlight. Thanks in advance.
JT

You should research Glocks law enforcement and military discount program. Other professions also qualify. I got my Glock 19 new with 3 magazines for $398.41. Had to go to a LE dealer, but it was worth the drive. Don't know if you would qualify, but it would be worth knowing about it. Good luck.

SMann,
Thanks for your reply. I'm a public high school teacher in SE TX. This will be will be CCW/SD pistol. With so many brands of semiauto pistols out there, it's mind boggling process of researching and readings. It would be somewhat easier if I had some friends that shoot hand guns but I don't. I've just moved to Huntsville, TX. and I really don't know many people here. I have quite a few weapons but my only pistol is my 9mm Norinco Tokerev, I purchased in the mid 90's. A decent pistol especially for what I paid for it NIB for $110 w/nice hard plastic carry case. I haven't set my decision soley on a Glock. I'm in no extreme hurry and have no real issues making me want/need to carry. So I'll continue my search. School/work is out of the question, all I'd have to due is walk across the street to check myself in to Texas' Maximum Security State/Federal prison, if I took a weapon on campus. I'm too old to be Bubba's prison......
JT